1. Field of the Invention
This invention relates generally to quick application/release fasteners and more particularly to a nut that allows a fastener to be inserted or removed from either side by simply sliding the fastener in or out and includes a visual in dicator of positive engagement.
2. Brief Description of the Prior Art
Conventional nuts for fastening objects together have the disadvantage of requiring a large number of turns to position in a fully locked position. This may also involve the application of a considerable amount of torque. Mechanical operations in space, i.e., at low gravity, r problems which do not exist on earth. For example, when one applies torque, as in tightening a threaded nut or joint a countertorque is encountered against the worker (Newton's third law) which tends to rotate the worker around the object being torqued as much as to tighten the threaded joint.
In space activities by NASA or other space exploratory entities, an astronauts' time is valued at up to $100,000 per hour. The above-noticed problems have created a demand in astronautic activities to overcome both the physical problem caused by Newton's third law and the cost involved in the time required by the astronaut/worker in tightening a threaded joint or fastener.
A partial solution to the problems discussed above is the use of one of several known quick application nuts in making threaded assemblies.
There are several patents which disclose various types of quick application nuts for making threaded assemblies.
German Patent 1,928,490 discloses a nut which ensures rapid transversal of a spindle until a load is met. A sliding sleeve at the base of the nut is forced in as the nut contacts a surface at its base. The further movement of the sleeve inward forces threaded sections of the nut to be wedged into positive engagement with the screw spindle. The device includes springs that bias the threaded sections outward and apart, and a spring that presses the threaded sections down against the sleeve so that it extends out from the bottom of the nut.
Morin U.S. Pat. No. 3,385,338 discloses a lock nut structure having a threaded wedge member forced into positive engagement with the threads of a bolt as the lock nut is tightened. When the nut is positively engaged, the top of the wedge member protrudes from the top of the nut.
Fullerton U.S. Pat. No. 4,378,187 discloses a multifaceted casing having a wedge fit threaded jam nut for compressing into engagement on the threads of a bolt as the nut is tightened into a locked position.
These nuts or fasteners function satisfactorily on insertion or application of the quick-application nut but do not provide for both quick application and quick release, are not constructed for insertion from either side, and do not have a positive engagement indicator.
The present invention is distinguished over the prior art in general, and these patents in particular by providing a composite nut which permits a fastener to be inserted or removed from either side with an indicator of fastener engagement. The nut has plurality of segments, preferably at least three segments, which are internally threaded, spring-loaded apart by an internal spring, and has detents on opposite sides which force the nut segments into operative engagement with a threaded member when pushed in and release the segments for quick insertion or removal of the nut when moved out. When the nut is installed, end pressure on one of the detents presses the nut segments into operative engagement with a threaded member where continued rotation locks the structure together with the detents depressed to indicate positive locking engagement of the nut. On removal, counterclockwise rotation of the nut relieves the endwise pressure on the detents permitting internal springs to force the detents outward and allowing the nut segments to move outward and separate to permit quick removal of the fastener.